This invention relates to methods for determining pregnancy or reproductive status in mammals such as cattle and, more particularly, to such methods which are novel and which provide a relatively simple and clear-cut interpretation of the reproductive status of mammals.
In the past, there have been various test methods for determining the status of mammalian females in their reproductive cycle, i.e. fertile period, non-fertile period, pregnancy, and abnormal conditions.
In general, such prior methods have been species dependent, but typically involve cyclic physiological or behavioral events such as menstrual periods in humans and primates and estrus behavior in domestic animals. Manual palpation of the reproductive tract and associated structures has been the accepted diagnostic method with large domestic animals and laproscopic techniques have been applied to many species. More recently, hormone assays of body fluids have been used experimentally with several species. These assays, while believed to be accurate, are generally quite time-consuming.
The observational methods of the prior art as applied to domestic animals are reported to be only 60% effective. Further, manual palpation is skill-limited and, moreover, is typically used for pregnancy diagnosis only after approximately 40 days past breeding. Laproscopy has the disadvantage of involving surgical procedures. Finally, hormone assays generally are still experimental procedures and as with progesterone, they may be effective only during brief specific time periods.
Illustrative prior art patents in this field include U.S. Pat. No. 3,826,616, U.S. Pat. No. 3,926,037, U.S. Pat. No. 3,955,928, U.S. Pat. No. 3,982,423, U.S. Pat. No. 3,979,945 and U.S. Pat. No. 4,016,250.
Attention is also directed to a publication by Katz et al. Biology of Reproduction 17, 843-849 (1978) entitled "Water Mobility Within Bovine Cervical Mucus" which deals with the self-diffusion coefficient of water with sperm-free bovine cervical mucus measured by pulsed-gradient nuclear magnetic resonance (NMR) spectroscopy; and Odeblad et al. Chapter 14 entitled "Types of Cervical Secretions: Biophysical Characteristics" from "The Biology of the Cervix", The University of Chicago Press (1973).
There remains, therefore, an unfulfilled need for a simple and clean-cut procedure of acceptable reliability for determining the reproductive status of female mammals.